1. Field of the Invention
The invention relates to a processing device for comminuting, disintegrating, transporting and plastifying and granulating or for agglomeration of plastic material, in particular of the thermo-plastic kind, comprising a comminuting device with the charging device and a worm extruder.
2. Brief Description of the Background of the Invention Including Prior Art
It is usual in connection with the reprocessing of plastic stock to comminute the plastic stock in a mill and to transport the plastic stock into a silo. The pre-comminuted plastic stock is fed from the silo to an extruder through a plugging machine. This configuration is associated with the advantage that the silo furnishes a storage capacity for balancing variations in the quantity of charge material.
It is a disadvantage of the arrangement to have a bad thermal degree of effectiveness since that the comminution energy, which transfers in the form of frictional heat in the mill onto the plastic material, and which comminution energy is delivered again into the environment based on a further intermediate storage in the storage silo and thereby is lost for the extrusion process. This arrangement is further associated with a disadvantage that a substantial space requirement exists.
In addition devices are known where the plastic material to be reprocessed falls from above into a container, wherein a knife disk rotates on the floor of the container, wherein the material is pre-comminuted with the knife disk and is pressed through an opening disposed in the container wall, where the plastic material is taken up by a worm extruder and is further processed.
It is an advantage of such an arrangement that the comminution energy, which comminution energy enters into the material to be processed in the kind of frictional heat, can be used in the extrusion process. However, the limitation of the size of the material parts with which this arrangement can be fed and the requirement of a continuously uniform charging are a very important disadvantage, because otherwise quickly an overload of the drive motor occurs and interferences of the material preparation and of the material throughput can occur, which are associated with the consequences of output and yield variations and the formation of densified pieces or even at least in part molten up plastic material. Therefore the plastic material to be processed has to be fed in small pieces or particles into the charge container in connection with this arrangement.
The thereby required separation of the comminuted material depending on the size of the pieces becomes expensive and complicated in most cases however, in particular in case of pressed plastic material or in case of large solid parts, because these have to be separated either manually or automatically, whereby a substantial requirement to the workforce or, respectively, an additional important equipment requirement in the form of a coarse comminuting machine becomes necessary.
There is a further known device for the processing of plastic material and filler material such as for example sawdust. The still wet material is to be pre-dried and to be transported in an extruder.
Here exists the disadvantage that the suitable size of the material is limited for the charging, because here also the material passes into the charge funnel based on gravity and an overload of the motor can occur in case of material pieces of too large size.
According to another device for processing of plastic material, a charge device is predisposed to a processing drum furnished with knives, wherein the material collection or the supporting transport wings of a transport screw transport the comminuted material through an opening of the conveyor tube into a worm extruder. The material is plastified and granulating upon passage through the extruder.
The drive expenditure is important in connection with this arrangement, since the extruder and the processing drum have to be driven separately. In addition, there is the necessity that the distances between the transporting parts of the processing drum and of the extruder worm are to be as small as possible in order to always assure that the transfer occurs without problem, which renders necessary an expensive construction.
Substantial counter forces occur finally at the end of the transport path at the processing drum, which counter forces have to be decreased by constructive steps, in particular the unloading of the bearings and the sealing of the bearings.